化妆品植物原料(V)——抗氧化活性的植物原料的研究与开发

Botanical cosmetic ingredients(V)Research and development of plant antioxidants

生物氧化是机体在新陈代谢过程中物质氧化产生能量的一系列氧化还原反应。皮肤细胞通过代谢或在外界侵袭下不断产生高活性的自由基和ROS。过度产生的这些高活性分子可影响细胞结构发生改变,导致细胞过早死亡,引发皮肤问题。而抗氧化剂有助于提高机体的抗氧化能力,消除自由基和ROS的有害影响。本文综述了自由基和ROS、氧化应激、氧化损伤及其引起的皮肤病和抗氧化的机理。主要介绍具有抗氧化活性的植物提取物,包括酚类、酚酸类、黄酮类、二苯乙烯类、原花青素、类胡萝卜素和维生素等。其中,酚类化合物占主导地位;大多数多酚以共轭结构形式存在,具有很好的抗氧化活性。这些天然抗氧化剂的结构特点是存在酚羟基或不饱和共轭双键。抗氧化剂的抗氧化活性越好,则越容易被还原,其结构也越不稳定。同时兼具水溶性和脂溶性特性的羟基酪醇拥有很强的抗氧化能力,而脂溶性成分虾青素和水溶性成分维生素C等也具有很好的抗氧化活性。同时对一些植物成分的抗氧化机制进行了阐述,希望为植物提取物更好地应用到相关化妆品提供借鉴。

Biological oxidation is an energyproducing reaction in the metabolism of living organisms.Under cellular metabolism or extracellular stress,the skin cells continuously produce highly active free radicals and reactive oxygen species.Over-producing these highly active molecules causes cell structure changes,leading to early apoptosis and skin problems.Antioxidants help to improve the antioxidant capacity of the organisms and eliminate the harmful effects of free radicals and reactive oxygen species.Herein,free radicals and reactive oxygen species,oxidative stress,oxidative damage and the skin diseases caused by them,as well as the mechanisms of antioxidant action,have been reviewed.The plant extracts with antioxidant activity have been mainly introduced,including phenols,phenolic acids,flavonoids,stilbenes,procyanidin,carotenoids and vitamins.Among them,phenolic compounds are most important.Most polyphenols exist in conjugated forms and exhibit excellent antioxidant activity.The common structural feature of these natural antioxidants is the presence of phenolic hydroxyl groups or conjugated double bonds.For an antioxidant,the better the antioxidant effect it has,the easier it is to be reduced.The hydroxytyrosol,which is both water-and fatsoluble,has strong antioxidant capacity.The fat-soluble astaxanthin and water-soluble vitamin C also show good antioxidant activity.The antioxidation mechanisms of some plant ingredients have been described to provide reference for the application of plant extracts as antioxidants in cosmetics.